/Engine/Source/Runtime/Engine/Classes/GameFramework/LightWeightInstanceStaticMeshManager.h
Adds a new instance at the specified index. This function should only be called by AddNewInstance. Provided to allow subclasses to update their per instance data
virtual void AddNewInstanceAt ( [FLWIData](API\Runtime\Engine\GameFramework\FLWIData) * InitData, int32 Index )